This invention relates to the field of rocket propulsion, and more particularly steering of rocket propelled missiles or vehicles by thrust vector control.
Thrust vector control with large deflection angles (.+-.20.degree. and more) has, in the past, required the use of gimballed rocket motors or gimballed nozzles with the associated complexity of gimbal servos and related precision mechanisms that are exposed to large forces. The use of secondary injection of fluids such as liquids or cold or hot gas generally limits the thrust vector control deflection angle to approximately .+-.6.degree..
There has therefore existed an unfulfilled need for a thrust vector control system that can operate reliably, rapidly and effectively to produce not only a relatively constant axial thrust, but also thrust vectors that yield the lateral forces necessary for desired pitch, yaw and roll maneuvers without the complex mechanization associated with the gimballed systems. In answering that need, an additional and important consideration is a need for compatability with propulsion gas generators of the constant burn rate type. Such compatability requires a substantially constant level of total utilization of the gas generator output irrespective of modulation or apportionment between different thruster nozzles during various maneuvers.